Electrical connection means in ignition coil unit or the like



March 23, 1965 w. o. HENSCHKE 3,175,175

ELECTRICAL CONNECTION MEANS IN IGNITION COIL UNIT OR THE LIKE Filed June 2. 1961 INVENTOR. WILLIAM O. HENSCHKE W3 M 611 Q4 United States Patent Ofilice 3,175,176 Patented Mar. 23, 1965 3,175,176 ELECTRICAL CONNECTION MEANS IN lGNlTiQN COEL UNIT OR THE LEKE William O. Henschke, Longmeadow, Mass, assignor to R. E. Phelon Company, Ina, Longmeadow, Mass, a

corporation of Massachusetts Filed June 2, 1961, Ser. No. 114,374 Claims, (Cl. 336-192) This invention relates generally to an ignition coil unit comprising primary and secondary electrical coils which are embedded in a molded body of insulating material and which may be included in a flywheel type magneto with a stator core and a rotor, and operatively associated with an ignition wire leading to a spark plug of an internal combustion engine. Such a coil unit is shown in a hywheel type magneto in operative association with an ignition Wire in Patent No. 2,968,777 to Russell E. Phelon, entitled Wire Retaining Means for an Ignition Coil Unit.

More particularly, the invention relates to and has as its general object the provision of an improved means in an ignition coil unit or the like for effecting an electrical connection with an ignition or other wire.

The drawing shows a preferred embodiment of the invention and such embodiment will be described, but it will be understood that various changes may be made from the construction disclosed, and that the drawing and description are not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

In the drawing:

FIG. 1 is a prespective view of an ignition coil unit constructed in accordance with the invention.

FIG. 2 is a bottom view of the coil unit showing to advantage an empty conductor receiving socket or openmg.

FIG. 3 is a vertical section taken generally as indicated at 33 in FIG 2 with a conductor in the socket.

FIG. 4 is a fragmentary vertical section similar to FIG. 3, but showing the socket empty.

FIG. 5 is an enlarged fragmentary horizontal section taken generally as indicated at S5 in FIG. 3.

FIG. 6 is an enlarged fragmentary section similar to FIG. 5, but shows a second and larger conductor in the socket.

Referring particularly to FIG. 3, it will be observed that an ignition coil unit indicated generally at it) comprises primary and secondary electrical coils l2 and 14. The coils 12. and 14 respectively have a relatively small and a relatively large number of turns, as for example 175' and 10,000. Said coils may be associated with a magneto stator core and rotor as disclosed in the aforementioned patent. In addition, the primary coil 12 may have a ground connection and a connection with a breaker device in the magneto and the secondary coil 14 may also have a ground connection in accordance with the patent. Thus, connection of the secondary coil with an ignition wire or conductor can be effected through a tack 15.

The tack 16 is electrically conductive and is shown as being generally U-shaped. One end portion 18 of the tack may be electrically connected with the secondary coil 14 as shown to provide for conduction through a body portion 20- thereof to a pointed end portion 22 and thence to an ignition wire or conductor 24.

Still referring to FIG. 3, it will be observed that the primary and secondary coils l2 and 14 are embedded in a molded body 26 of insulating material. The body 26 of the coil unit may include a shell 28 and a filler section 30 and it is preferably generally cylindrical in shape as best shown in FIG. 2. A square central opening 32 which extends vertically through the body 26 may receive a portion of a stator core as indicated in the aforesaid patent.

In accordance with the present invention, the body 26 of the coil unit 10 is also provided with a socket or opening 34 of a particular shape and size and in which the ignition wire or conductor 24 may be entered and secured. The socket or opening 34 extends vertically upwardly in the body as shown and it is closed at its upper end by a wall 36. The aforementioned pointed end portion 22 of the tack 16 projects centrally downwardly into the socket or opening 34 from the end Wall 36 and the remaining portions 18 and 20 of the tack are embedded in the body 26.

Now it will be apparent that an end portion of an elongated conductor including a central core and a cylindrical insulating sheath can be entered upwardly in the opening 34 so that its core will be engaged with the tack end portion 22 to provide an electrical connection. This appears to be a simple and efiective method of making an electrical connection and it has many advantages. However, there are also problems involved in this type of socket and tack connection. The insulating sheaths of conductors usable for ignition wires and like purposes ordinarily vary significantly in outside diameter due to manufacturing tolerances and the like. Thus, a socket or opening such as that shown at 34 must in effect be capable of selectively receiving 'a plurality of conductors having insulating sheaths of different diameters. If a cylindrical socket is provided of such diameter that all conductors encountered fit loosely therein, the smaller size conductors will have excessively large spaces adjacent their peripheral surfaces. More importantly, the wall of such a socket cannot serve as a guide in engaging the central cores of such smaller conductors with the projecting tack end portion. Thus, it may be difiicult if not impossible to properly engage and electrically connect the tack with the core of a small diameter conductor. If on the other hand, a socket is provided which permits effective insertion and attachment of the smaller conductors but which entails a tight fit of the larger diameter conductors, air may be trapped between the upper end of such a large conductor and the upper or closed end wall of the socket. As in the case of most electrical devices, ignition coil unit can be expected to encounter elevated temperatures and entrapped air will of course expand tending to force the large conductor downwardly out of its socket and possibly disengaging the conductor core from the tack.

In further accord with the present invention, the aforesaid socket or opening is provided in a cross-sectional shape w ich differs from that of the conductors to be entered therein and deformability of the conductor insulating sheaths is taken advantage of to provide for effective electrical connection with the tack 16 of conductors with significantly different outside diameters. The shape of the socket or opening is such that its cross-sectional area is larger than that of the largest diameter conductor to be encountered and this eliminates any possibility of entrapment of air and the undesirable results mentioned above. Further, the socket is so formed that it has at least two and preferably three longitudinally extending wall portions which engage the peripheral surface of the smallest conductor or the conductor with the smallest diameter insulating sheath. By engagement with the said wall portions, the conductor is guided during insertion into the socket so that its central core is positively engaged with the centrally projecting tack portion and an efiective electrical connection is assured.

Referring now to FIGS. 5 and 6, it will be observed that the socket 34 is generally hexagonal in cross-sec tional shape with alternate longitudinally extending walls or wall portions 38, 38 and intermediate longitudinally extending walls or wall portions 40, it). The alternate wall portions 38, 38 are preferably fiat as shown and the intermediate portions 40, 4t) are preferably of shallow concave configuration and extend in a common cylinder. A conductor 24 shown in FIG. 5 may be taken to represent the smallest of the conductors provided for insertion in the socket and a conductor 24 in FIG. 6 may be taken as the largest of the conductors provided for insertion in said socket.

Each of the conductors 24 and 24 comprises a stranded central core 4-2 and each conductor has a relatively soft deformable insulating sheath of circular cross section. Said insulating sheaths are identical in all respects except that a sheath d4 of the conductor 24 is slightly smaller in outside diameter than a sheath 44 of the conductor 24 this diflierence resulting from manufacturing tolerances or the like as mentioned.

By inspection it will be clear that even the smallest conductor 24 will be guided and centered by the wall portions 38, 38 during insertion in the socket 34 so that its core will be engaged and electrically connected with the tack portion 22 as shown in FIG. 3. Larger conductors including the aforesaid largest conductor 24 will be similarly guided with a slight compression and deformation of their insulating sheaths. In all cases there will be three elongated spaces adjacent the peripheral surface of a conductor entered in the socket 34 and respectively adjacent the three wall portions 4 4%. Moreover, said spaces will be of substantially uniform thickness throughout their length and width.

The provision of the three elongated spaces adjacent the conductor serves an important purpose in that a filler can be deposited therein. The filler 45 may comprise merely a sealing compound, but it is preferably a combined sealer and adhesive. In accordance with the presently preferred practice, the filler is spread substantially uniformly and in a fluid state on the aforesaid Walls of the socket and squeezes or flows into the said spaces during insertion of a conductor in the socket. It is found that the filler thus applied does not prevent the escape of air from the socket during insertion of a conductor and yet serves thereafter to harden and to completely fill and seal the spaces adjacent the conductor. Thus, the connection between the tack and the conductor is isolated to prevent electrical leakage and, in the case of a combined sealer and adhesive, the conductor is secured in place by the filler as well as by frictional forces.

The invention claimed is:

1. In an ignition coil unit or the like adapted for selective connection with a plurality of elongated conductors having central cores Within deformable generally cylindrical insulating sheaths of different diameters; the combination of an electrically conductive tack having a pointed end portion, a molded body of insulating material with an elongated noncircular opening therein for selectively receiving longitudinally inserted end portions of said conductors, said opening having a transverse end wall and a side Wall continuous through 360, said tack being partially embedded in said body With its pointed end portion projecting longitudinally and centrally into said opening from its end wall so as to engage and enter longitudinally the central core of a conductor inserted longitudinally in the opening, and said opening having a cross-sectional area greater than that of the conductor with the largest diameter insulating sheath and having at least three longitudinally extending side wall portions equally spaced transversely from said tack and spaced transversely from each other so as to engage the peripheral surface of the condoctor with the smallest diameter insulating sheath, and a filler adapted to be disposed in said opening to seal spaces between a conductor disposed therein and the wall of the opening.

2. In an ignition coil unit or the like adapted for selective connection with a plurality of elongated conductors having central cores Within deformable generally cylindrical insulating sheaths of different diameters; the combination of an electrically conductive tack having a pointed end portion, a molded body of insulating material with an elongated noncircular opening therein for selectively receiving longitudinally inserted end portions of said conductors, said opening having a transverse end Wall and a side wall continuous through 360, said tack being partially embedded in said body with its pointed end portion projecting longitudinally and centrally into said opening from its end wall so as to engage and enter longitudinally the central core of a conductor inserted longitudinally in the opening, and said opening having a cross-sectional area greater than that of the conductor with the largest diameter insulating sheath and having three longitudinally extending side wall portions equally spaced transversely from said tack and spaced transversely from each other so as to engage the peripheral surface of the conductor with the smallest diameter insulating sheath, and a filler adapted to be disposed in said opening to seal spaces between a conductor disposed therein and the wall of the opening.

3. in an ignition coil unit or the like adapted for selective connection with a plurality of elongated conductors having central cores within deformable generally cylindrical insulating sheaths of different diameters; the combination of an electrically conductive tack having apointed end portion, a molded body of insulating material with an elongated generally hexagonal opening therein for selectively receiving longitudinally inserted end portions of said conductors, said opening having a transverse end wall and a side Wall continuous through 360, said tack being partially embedded in said body with its pointed end portion projecting longitudinally and centrally into said opening from its end wall so as to engage and enter longitudinally the central core of a conductor inserted longitudinally in the opening, and said opening having a cross-sectional area greater than that of the conductor with the largest diameter insulating sheath and having three longitudinally extending side Wall portions equally spaced trannsversely from said tack and spaced transversely from each other so as to engage the peripheral surface of the conductor With the smallest diameter insulating sheath, and a filler adapted to be disposed in said opening to seal spaces between a conductor disposed therein and the Wall of the opening.

4. In an ignition coil unit or the like adapted for selective connection With a plurality of elongated conductors having central cores Within deformable generally cylindrical insulating sheaths of different diameters; the combination of an electrically conductive tack having a pointed end portion, a molded body of insulating material With an elongated generally hexagonal opening therein for selectively receiving longitudinally inserted end portions of said conductors, said opening having a transverse end wall and a side wall continuous through 360, said tack being partially embedded in said body with its pointed end portion projecting longitudinally and centrally into said opening from its end wall so as to engage and enter longitudinally the central core of a conductor inserted longitudinally in the opening, and said opening having a cross-sectional area greater than that of the conductor with the largest diameter insulating sheath and having three alternate and three intermediate longitudinally extending side wall portions, said alternate side wall portions being equally spaced transversely from said tack and spaced transversely from each other so as to engage the peripheral surface of the conductor with the smallest diameter insulating sheath, and said intermediate side wall portions being arranged so as to be spaced from the peripheral surface of the conductor with the largest diameter insulating sheath, and a filler adapted to be disarrears posed in said opening to seal spaces between a conductor disposed therein and the wall of the opening.

5. In an ignition coil unit or the like adapted for selective connection with a plurality of elongated conductors having central cores Within deformable generally cylindrical insulating sheaths of ditferent diameters; the combination of an electrically conductive tack having a pointed end portion, a molded body of insulating material with an elongated generally hexagonal opening therein for selectively receiving longitudinally inserted end portions of said conductors, said opening having a transverse end wall and a side Wall continuous through 360, said tack being partially embedded in said body with its pointed end portion projecting longitudinally and centrally into said opening from its end wall so as to engage and enter longitudinally the central core of a conductor inserted longitudinally in the opening, and said opening having a cross-sectional area greater than that of the conductor with the largest diameter insulating sheath and having three alternate and three intermediate longitudinally extending side wall portions, said alternate side wall portions being equally spaced transversely from said tack and spaced transversely from each other so as to engage the peripheral surface of the conductor With the smallest diameter insulating sheath, and said intermediate side Wall portions being of shallow concave cross-sectional configuration which provide elongated spaces of substantially uniform thickness adjacent the peripheral surface of any one of said conductors when the conductor is entered in said opening, and a filler adapted to be disposed in said opening to seal spaces between a conductor disposed therein and the wall of the opening.

References Cited in the tile of this patent UNITED STATES PATENTS 916,313 Herrington Mar. 23, 1909 1,244,642 Pruessman Oct. 30, 1917 2,675,531 Sams et al Apr. 13, 1954 2,751,568 Despard June 19, 1956 2,968,777 Phelon Ian. 17, 1961 

1. IN AN IGNITION COIL UNIT FOR THE LIKE ADAPTED SELECTIVE CONNECTION WITH A PLURALITY OF ELONGATED CONDUCTORS HAVING CENTRAL CORES WITHIN DEFORMABLE GENERALLY CYLINDRICAL INSULATING SHEATHS OF DIFFERENT DIAMETERS: THE COMBINATION OF AN ELECTRICALLY CONDUCTIVE TACK HAVING A POINTED END PORTION, A MOLDED BODY OF INSULATING MATERIAL WITH AND ELONGATED NONCIRCULAR OPENING THEREIN FOR SELECTIVELY RECEIVING LONGITUDINALLY INSERTED END PORTIONS OF SAID CONDUCTORS, SAID OPENING HAVING A TRANSVERSE END WALL AND A SIDE WALL CONTINUOUS THROUGH 360*, AND TACK BEING PARTIALLY EMBEDDED IN SAID BODY WITH ITS POINTED END PORTION PROJECTING LONGITUDINALLY AND CENTRALLY INTO SAID OPENING FROM ITS END WALL SO AS TO ENGAGE AND ENTER LONGITUDINALLY THE CENTRAL CORE OF A CONDUCTOR INSERTED LONGITUDINALLY IN THE OPENING, AND SAID OPENING HAVING A CROSS-SECTIONAL AREA GREATER THAN THAT OF THE CONDUCTOR WITH THE LARGEST DIAMETER INSULATING SHEATH AND HAVING AT LEAST THREE LONGITUDINALLY EXTENDING SIDE WALL PORTIONS EQUALLY SPACED TRANSVERSELY FROM SAID TRACK AND SPACED TRANSVERSELY FROM EACH OTHER SO AS TO ENGAGE THE PERIPHERAL SURFACE OF THE CONDUCTOR WITH THE SMALLEST DIAMETER INSULATING SHEATH, AND A FILLER ADAPTED TO BE DISPOSED IN SAID OPENING TO SEAL SPACES BETWEEN A CONDUCTOR DISPOSED THEREIN AND THE WALL OF THE OPENING. 